The invention relates to a collapsible multi-purpose ladder, the ladder stringers of which are connected by joints which are arranged in pairs and are releasably lockable in several operating positions. The joints each have two joint parts which are pivotal about a common joint axle. A first joint part has a two-cup locking disk which is concentric with respect to the joint axle and, along its circumference, has notches which are distributed to correspond to the respective operating positions. The notches can receive a spring-loaded locking part which is guided for longitudinal movement on the second joint part, which grips over the first joint part. The locking part can be moved out of a notch of the locking disk by a release lever which is swingably supported on the second joint part, the release levers of the two joints being connected by a rod. Such a multi-purpose ladder is known from German Offenlegungsschrift No. 27 54 755.
The connecting rod of this ladder extends inside a ladder stringer, whereby the operation of the release lever occurs with control grips which are arranged on the sides of the ladder stringers. This conventional joint arrangement is structurally expensive to manufacture and is susceptible to breakdown during operation.
A basic purpose of the invention is to provide a collapsible multi-purpose ladder of the above-mentioned type in which the joints are structurally simple and the ladder can be operated easily.